Self-filling bottom-dumping front end loader



Sept. 28, 1965 oeus 3,208,610

SELF-FILLING BOTTOMDUMPING FRONT END LOADER Filed Sept. 7, 1962 UnitedStates Patent 3,208,610 SELF-FILLING BOTTOM DUMPING FRONT END LOADERAnthony T. Logus, Chicago, Ill., assignor to Pettibone MullikenCorporation, a corporation of Delaware Filed Sept. 7, 1962, Ser. No.222,040 8 Claims. (Cl. 214140) Front end loaders are those widely knownself-propelled vehicles having a big scoop or bucket on arms at thefront end. When a pile of material is to be loaded into a truck, thefront end loader may propel itself to push the bucket into the pile atthe bottom of the pile. As the arms are raised to fill the bucket fromthe pile, the vehicle pushes itself further forwardly to assist in thebucketfilling task. When thebucket has been filled, the vehicle usuallybacks itself away, raises the bucket to full height, moves the bucketover a truck, and dumps the bucket by tilting it downwardly. Quite a fewvariations of this general type of front end loader have been marketed,and the total number sold is no doubt many thousands. The front endloader might well be considered to have been quite adequately perfected.

According to the present invention, some simple changes have improvedthe front end loader to a surprising degree. One change consists inpivoting the lift arm to the bucket at a point on the top of the bucketand near its forward face when in digging position. This pivotalposition has the result of causing the bucket, when tilted by a tiltcylinder without raising the lift arm to reach further into the pile asit is uprighted. Approximately 90 tilting or tilt back from a horizontalapproaching to a vertical carrying disposition can easily be provided.As a result, the vehicle rarely needs to be crowded forwardly as thebucket is raised. With a reasonably steepfaced pile, the bucket isself-filling in that merely by its tilting action, it scoops from thepile a full load, even though not driven into the pile initiallyfarvenough to constitute any severe burden on the driving parts or othermechanism or to make break out difficult. This not only simplifiesoperation, but saves a great deal of wear and tear on the vehicle and,on the average, makes the loading operation slightly faster.

Another change compared to the more common versions of front end loaderis to provide for dumping the bucket by opening its bottom panel whilethe bucket, as a whole, remains stationary. These features combine toprovide an advantage of higher clearance of the bucket over a truck thanwould be possible after the conventionally pivoted bucket had tilteddownwardly from the upright position to a dumping position.

The fact that the bucket is to be dumped by opening its bottom permitsgiving it a shape which in cooperation with the 90 tilt back permittedby its mounting makes best use of its self-filling characteristics, andpermits low carrying with little or no spilling, even with a full load.The bottom dumping also avoids a dumping problem which would otherwiseexist when the bucket is pivoted near the upper front corner, theposition of pivoting which best provides the self-fillingcharacteristics, but which would tend not to let the bucket swing downand back far enough for adequate dumping.

Operators accustomed to conventional front end loaders have now used thefront end loaders with the above described features of this inventionfor some months and have been amazed at the improved operation whichresults.

Additional objects and advantages of the invention will be apparent fromthe following description and from the drawings.

Designation of figures FIGURE 1 is a side elevational view of a frontend loader chosen for illustration of the present invention, most of therear portion of this vehicle being omitted, the arms being shown innormal position and the bucket tilted back for approaching a pile.

, FIGURE 2 is a fragmentary view similar to FIG. 1, but showing thebucket tilted forwardly to the loaded position.

FIGURE 3 is a fragmentary view similar to FIGS. 1 and 2, but showing thelift arms in the uppermost position and the bucket bottom open fordumping.

General description Although the following disclosure offered for publicdissemination is detailed to ensure adequacy and aid understanding, thisis not intended to prejudice that purpose of a patent which is to covereach new inventive concept therein no matter how others may laterdisguise it by variations in form or additions or further improvements.The claims at the end hereof are intended as the chief aid toward thispurpose; as it is these that meet the requirement of pointing out theparts, improvements, or combinations in which the inventive concepts arefound.

The illustrated form of front end loader includes a vehicle chassis 11which includes front wheels 12 and rear wheels 13. At least one set ofthe wheels is driven and at least one set is turned to right or left forsteering. Dependlng on the uses expected, all four may be driven and allfour may be steerable. Preferably, an operators cab 14 is provided onthe chassis, and there will at least be an operators seat, steeringwheel and various control levers and pedals at the general positionrepresented by the cab 14.

A lift arm 16 is pivoted at a reasonably high location on the chassis,as to a pedestal 17. A bucket or scoop 18 is pivoted to the front end ofthe lift arm 16. The present invention contemplates a construction inwhich one pair of cylinders 19 will raise and lower the lift arm 16, anda separate cylinder or pair of cylinders 21 will swing the bucket 18about its pivotal connection to lift arm 16. It may be noted that onlyone side of the machine is shown and many of the parts are duplicated onthe opposite side. The lift arm 16 may be spoken of in the singular orin the plural, inasmuch as there are usually two longitiudinal membersspaced apart but functioning together with firm connecting members as asingle structure.

Self-filling feature According to the present invention, the pivotalconnection 23 between the bucket and the lift arm 16 is located near thetop front corner of the bucket, referring to the bucket in the approachposition shown in FIG. 1. How far forwardly this pivotal axis is locatedwill depend largely on how completely one desires to make use of thisaspect of the invention. From FIG. 1 it is apparent that the pivotalaxis is only something like 28 behind the vertical from the lip 24 ofthe bucket. It follows that with lift arm 16 remaining stationary andthe vehicle remaining stationary, actuation of tilt cylinders 21 to tiltbucket 18 will cause its lip 24 to move in a direction which isinitially very predominantly forwardly. The are of movement of the lip24 is indicated at 26. It may be observed that this are of movement, andespecially the lower half of it, is roughly parallel to the angle ofrepose which may be expected in many piles of material. It follows thatif the vehicle is initially moved to bury the lip of the bucketmoderately in the pile of material to be loaded into the bucket, thevehicle may remain stationary and the tilting action of the bucket willcrowd the lip into the pile as the lip is raised.

It has been found from experience that the bucket can usually becompletely filled, or filled with a heaping load, in this manner. InFIG. 2 the bucket has been swung to the filled position with its openface horizontal, the cylinders 21 being fully extended. The liftcylinders 19 remain fully retracted, the lift arms 16 still being intheir lowermost position. The lip 24 remains within the pile, thusensuring a full load for the bucket 18.

In FIG. 3, the lift cylinders 19 have been extended to raise the liftarms 16 to its highest angularity. It will be observed that the openface of bucket 18 is still horizontal, the cylinders 21, their pistonrods 28 and connecting links 29 and 31 having served as self-levelinglinkage. The front pivot of link 29 is approximately the same distancefrom pivot 23 as the rear pivot 33 is from pivot 34. Likewise, pivot 36for piston rods 28 is about the same distance from pivot 34 as is pivot37, for cylinders 21, from main lift arm pivot 38. Thus, the pivots 23,32, 33 and 34 form one parallelogram While the pivots 34, 36, 37, 38form another parallelogram when the tilt cylinders 21 are extended, asthey are during this self-leveling action.

Bottom-dump feature As seen in FIG. 3, the bottom 41 of bucket 18 can betilted to a steep angle while the bucket remains in the uprightposition. To this end the bottom is pivoted at 42 and is operated bydump cylinders 43, which are connected to the bottom 41 through an arm44. Preferably, shields 46 are provided to control the direction inwhich the dumping material moves. Thus, as illustrated in FIG. 3 it allmoves forwardly under the influence of the sloping dropped bottom 41.This is desirable for obtaining full loads in trucks, with heaping atthe center area. Preferably, the dropped bottom 41 has an angularity ofapproximately 45 from the vertical, this being steep enough to ensureself cleaning of the material from the bottom 41 while still having thedesired forwardly projecting effect.

The power control of bottom 41 is useful in adjusting its slope forcontrolling the placing of the load. Also, when desired, the bottom maybe opened only slightly to control the rate or quantity of flow, or foracting as a grizzly to hold back large pieces to be separately disposedof. Also the bottom may be closed during dumping in case a truck isfilled before the bucket is empty.

Each of the functions described is preferably controlled by a separatevalve actuator, such as 45 within the reach of the driver of thevehicle. Preferably the tilt cylinder 21 is double-acting for reliablyswinging the bucket 18 to the position shown in FIG. 1. Althoughcylinders 19 and 43 could be single acting, return hoses are quitelikely to be provided for return of any oil which may leak past thepistons and to avoid the necessity of constant breathing beyond thepistons. Hence, it is not much more expensive to provide double-actingcylinders, and there is some advantage to doing so, especially in thecase of the lift cylinders 19.

When digging a hard packed bank of virgin gravel, the operator can stripthe bank several times with the door open, allowing the loosenedmaterial to pass freely through the bucket until a sulficient pile ofloose material has developed at the footing, which he then can loadeasily.

When employing an ordinary front end loader to strip a hard packed bankof virgin gravel, the operator finds this operation one of the mostdifficult and it is virtually impossible to fill the bucket.

Thus, the loader embodying this invention with the bottom dump bucketcan perform this function readily and do many jobs of this nature whichcannot be done with the ordinary front end loader, and on which jobs theordinary front end loader has had to give up.

If swinging from side to side is desired, the lift arm 16 may be carriedby a turntable, and all of its appurtenances may remain substantiallythe same except, perhaps, for the relocation of the lift cylinders 19,which would of course need to operate between the lift arms 16 and theturntable.

Conclusion The high and forward location of the pivot 23 between thebucket 18 and the lift arm 16 causes the forward tilting of the bucketto move the lip further into the pile for filling the bucket adequatelywithout continued crowding by the vehicle. The location of pivot ispreferably about as shown, though fair results may still be attained ifit is not over behind the vertical plane from the lip 24 when inpile-approaching position, and some advantage over prior art may beachieved even at about A pivotal point located further forward than the25 position may be even more advantageous in filling from piles havingnon-steep faces, but may be found to present other problems, thoughperhaps they can be overcome if need for such forward pivoting becomessignificant.

As seen in FIG. 3, this same preferred location of the pivot 23 is notwell adapted for letting the bucket swing far enough when the arm 16 israised to dump the bucket over the lip 24. The problem which might thusbe presented is solved by the provision of bottom dumping, and this hasother advantages. An exceptionally high clearance beneath the dumpingbucket in its uppermost position is achieved for any given length oflift arm 16. The dumping material is nevertheless projected forwardly,for best filling of a truck. Inasmuch as the wall 47 of the bucket doesnot have to be shaped with a view to ensuring its dumping of thematerial over the lip 24, it can be given the most desirable shape for aself-filling bucket. As seen best in FIG. 1, the portion of this wall 47rearwardly of a vertical plane through the axis of pivots 23 isapproximately arcuately shaped about this axis. This permits freedom ofswinging of the bucket 18. At the same time, as seen in FIGS. 2 and 3,wall 47 and the opposite wall are fairly close to vertical in theupright position of the bucket, so that a very large load can becarried, and so that the material will reliably dump from the bucket.

Of course, the structure represented by lift arms 16 and bucket 18 andthe appurtenances thereof, may be used advantageously with other loadingor material handling equipment in addition to the type commonly known asfront end loaders.

I claim:

1. Loading apparatus including a support, a lift arm pivoted to thesupport, hydraulic lift cylinder means for raising the lift arms from aposition in which they extend forwardly and downwardly from the pivotalpoint on the support to a position in which they extend forwardly andupwardly from said pivotal point, a bucket pivoted to the forward end ofthe lift arm, and an open face demarked by an entry lip along one sidethereof and facing mainly forwardly in one position of the bucket Withthe lift arm lowered, and hydraulic cylinder means independent of thelift cylinder means for controlling the angularity of the bucket withrespect to the lift arm to move the bucket to a position upright, withits open face facing upwardly,

in which the pivotal point between the bucket and the lift arm is on thetop of the bucket when the bucket is in the pile-approaching positionwith the lift arm down, and not over 45 behind a vertical plane withreference to the entry lip of the bucket whereby the pivoting of thebucket above swings the lip largely forwardly for penetration of a pileand to substantially fill the bucket as it is thus raised.

2. A front end loader including a self-propelled vehicle, a lift armpivoted to the vehicle and extending forwardly therefrom, hydraulic liftcylinder means for raising the lift arms from a position in which theyextend forwardly :and downwardly from the pivotal point on the supportto a position in which they extend forwardly and upwardly from saidpivotal point, a bucket pivoted to the forward end of the lift arm, andan open face demarked by an entry lip along one side thereof and facingmainly forwardly in one position of the bucket with the lift armlowered, and tilting means independent of the lift cylinder means forcontrolling the angularity of the bucket with respect to the lift arm tomove the bucket to a position upright, with its open face facingupwardly, in which the pivotal point between the bucket and the lift armis on the top of the bucket when the bucket is in the pile-approachingposition with the lift arm down,

and not over about behind a vertical plane with reference to the entrylip of the bucket, said tilting means inclu'ding'hydraulic cylindermeans for swinging the bucket forwardly from its entry positionindependently of movement of the lift arm, whereby the lip penetratesthe pile and substantially fills the bucket; said bucket having a wallmovable for opening the bucket at the bottom thereof when in the uprightposition.

3. Loading apparatus including a support, a lift arm pivoted to thesupport, hydraulic lift cylinder means for raising the lift arms from aposition in which they extend forwardly and downwardly from the pivotalpoint on the support to a position in which they extend forwardly andupwardly from said pivotal point, a bucket pivoted to the forward end ofthe lift arm, and an open face demarked by an entry lip along one sidethereof and facing mainly forwardly in one position of the bucket withthe lift arm lowered, and tilting means independent of the lift cylindermeans for controlling the angularity of the bucket with respect to thelift arm to move the bucket to a position upright, with its open facefacing upwardly,

in which the pivotal point between the bucket and the lift arm is on thetop of the bucket when the bucket is in the pile-approaching positionwith the lift arm down, and not over behind a vertical plane withreference to the entry lip of the bucket, said tilting means includinghydraulic cylinder means for swinging the bucket forwardly from itsentry position independently of movement of the lift arm, whereby thelip penetrates the pile and substantially fills the bucket as it is thusraised.

4. Loading apparatus including a support, a lift arm pivoted to thesupport, hydraulic lift cylinder means for raising the lift arms from aposition in which they extend forwardly and downwardly from the pivotalpoint on the support to a position in which they extend forwardly andupwardly from said pivotal point, a bucket pivoted to the forward end ofthe lift arm, and an open face demarked by an entry lip along one sidethereof and facing mainly forwardly in one position of the bucket withthe lift arm lowered, and tilting means independent of the lift cylindermeans for controlling the angularity of the bucket with respect to thelift arm to move the bucket to a position upright, with its open facefacing upwardly,

in which the pivotal point between the bucket and the lift arm is on thetop of the bucket when the bucket is in the pile-approaching positionwith the lift arm down, and not over 45 behind a vertical plane withreference to the entry lip of the bucket, said tilting means includinghydraulic cylinder means for swinging the bucket forwardly from itsentry position independently of movement of the lift arm, whereby thelip penetrates the pile and substantially fills the bucket; said buckethaving a panel hinged to the remainder of the bucket for opening thebucket at the bottom thereof when the bucket is upright.

5. Loading apparatus including a support, a lift arm pivoted to thesupport, hydraulic lift cylinder means for raising the lift arms from aposition in which they extend forwardly and downwardly from the pivotalpoint on the support to a position in which they extend forwardly andupwardly from said pivotal point, a bucket pivoted to the forward end ofthe lift arm, and an open face demarked by an entry lip along one sidethereof and facing mainly forwardly in one position of the bucket withthe lift arm lowered, and tilting means independent of the lift cylindermeans for controlling the angularity of the bucket with respect to thelift arm to move the bucket to a position upright, with its open facefacing upwardly,

in which the pivotal point between the bucket and the lift arm is on thetop of the bucket when the bucket is in the pile-approaching positionwith the lift arm down, and not over 45 behind a vertical plane withreference to the entry lip of the bucket, said tilting means includingpower means for swinging the bucket forwardly from its entry positionindependently of movement of the lift arm, whereby the lip penetratesthe pile and substantially fills the bucket; said bucket when in uprightposition having its bottom panel hinged at its rear to the remainder ofthe bucket for opening the bucket at the bottom thereof when the bucketis upright.

6. Loading apparatus including a support, a lift arm pivoted to thesupport, hydraulic lift cylinder means for raising the lift arms from aposition in which they extend forwardly and downwardly from the pivotalpoint on the support to a position in which they extend forwardly andupwardly from said pivotal point, a bucket pivoted to the forward end ofthe lift arm, and an open face demarked by an entry lip along one sidethereof and facing mainly forwardly in one position of the bucket withthe lift arm lowered, and tilting means independent of the lift cylindermeans for controlling the angularity of the bucket with respect to thelift arm to move the bucket to a position upright, with its open facefacing upwardly,

in which the pivotal point between the bucket and the lift arm is on thetop of the bucket when the bucket is in the pile-approaching positionwith the lift arm down, and not over 45 behind a vertical plane withreference to the entry lip of the bucket, said tilting means includingpower means for swinging the bucket forwardly from its entry positionindependently of movement of the lift arm, whereby the lip penetratesthe pile and substantially fills the bucket; said bucket when in uprightposition having its bot tom panel hinged at its rear to the remainder ofthe bucket for opening the bucket at the bottom thereof when the bucketis upright; and power means for adjusting the position of the bottompanel to control the quantity of flow and the slope of the bottom panel.

7. Loading apparatus including a support, a lift arm pivoted to thesupport, hydraulic lift cylinder means for raising the lift arms from aposition in which they extend forwardly and downwardly from the pivotalpoint on the support to a position in which they extend forwardly andupwardly from said pivotal point, a bucket pivoted to the forward end ofthe lift arm, and an open face demarked by an entry lip along one sidethereof and facing mainly forwardly in one position of the bucket withthe lift arm lowered, and tilting means independent of the lift cylindermeans for controlling the angularity of the bucket with respect to thelift arm to move the bucket to a position upright, with its open facefacing upwardly,

in which the pivotal point between the bucket and the lift arm is on thetop of the bucket when the bucket is in the pile-approaching positionwith the lift arm down, and not over 45 behind a vertical plane withreference to the entry lip of the bucket, said tilting means includingpower means for swinging the bucket forwardly from its entry positionindependently of movement of the lift arm, whereby the lip penetratesthe pile and substantially fills the bucket; said bucket having a wallmovable to open the bucket at its bottom when in the upright position.

8. Loading apparatus including a support, a lift arm pivoted to thesupport, hydraulic lift cylinder means for raising the lift arms from aposition in which they extend forwardly and downwardly from the pivotalpoint on the 7 8 support to a position in which they extend forwardlyand penetrates the pile and substantially fills the bucket upwardly fromsaid pivotal point, a bucket pivoted to the as it is thus raised.forward end of the lift arm, and an open face demarked by an entry lipalong one side thereof and facing mainly References Cited y the Examine!forwardly in one position of the bucket with the lift arm 5 UNITEDSTATES PATENTS lowered, and tilting means independent of the liftcylinder means for controlling the angularity of the bucket with respectto the lift arm to move he bucket to a Position g t 2T4 l3 l upright,with its open face fac g pw r y, 2861704 11/58 fi 14 14 in which thepivotal point between the bucket and the 10 28799O8 3/59 A O n n 214 131lift arm is on the top of the buck t Wh n the bucket 2961106 11/60Sal-sen 2 14-1716 X is in the pile-approaching position with the liftarm 3034671 5/62 L ,4 X

down, and not over about 30 behind a vertical plane with reference tothe entry lip of the bucket, said FOREIGN PATENTS tilting meansincluding power means for swinging the 15 855 128 11/60 Great Britainbucket forwardly from its entry position independently of movement ofthe lift arm, whereby the lip H SCHULZ, primary 1,504,427 8/24 Butler214-140

1. LOADING APPARATUS INCLUDING A SUPPORT, A LIFT ARM PIVOTED TO THESUPPORT, HYDRAULIC LIFT CYLINDER MEANS FOR RAISING THE LIFT ARMS FROM APOSITION IN WHICH THEY EXTEND FORWARDLY AND DOWNWARDLY FROM THE PIVOTALPOINT ON THE SUPPORT TO A POSITION IN WHICH THE EXTEND FORWARDLY ANDUPWARDLY FROM SAID PIVOTAL POINT, A BUCKET PIVOTED TO THE FORWARD END OFTHE LIFT ARM, AND AN OPEN FACE DEMARKED BY AN ENTRY LIP ALONG ONE SIDETHEREOF AND FACING MAINLY FORWARDLY IN ONE POSITION OF THE BUCKET WITHTHE LIFT ARM LOWERED, AND HYDRAULIC CYLINDER MEANS INDEPENDENT OF THELIFT CYLINDER MEANS FOR CONTROLLING THE ANGULARITY OF THE BUCKET WITHRESPECT TO THE LIFT ARM TO MOVE THE BUCKET TO A POSITION UPRIGHT, WITHITS OPEN FACE FACING UPWARDLY, IN WHICH THE PIVOTAL POINT BETWEEN THEBUCKET AND THE LIFT ARM IS ON THE TOP OF THE BUCKET WHEN THE BUCKET